High-efficiency led lamp

ABSTRACT

A high efficiency LED lamp includes a positioning frame base, LED bars, a light guide plate, a reflection sheet, an optical film, a power supply unit and a protective cover. The LED bars and the light guide plate are disposed at the inner side of the positioning frame base; the reflection sheet is stuck at one side of the light guide plate; the optical film is disposed at the other side of the light guide plate, and the protective cover is covered on foresaid members. The power supply unit is installed at the rear side of the positioning frame base for converting and supplying DC power for the LED bars. The optical film can be arranged in different modes for adjusting the lighting angles of the LED bars, and the power supply unit can function to supply steady DC power. The LED lamp of this invention can concentrate light and has excellent lighting effect.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a high-efficiency LED lamp, particularly toone employed for indoor illumination, able to concentrate light andelevate lighting efficacy.

2. Description of the Prior Art

Generally, an LED (light-emitting diode) has many special features, suchas low power consumption, power saving, long service life, simpleoperation and beneficial result of environmental protection.

Conventional lamps, such as tube lamps and lamp bulbs, are extensivelyemployed in various places for lighting, but the working efficiency ofthe conventional lamps can hardly reach a maximum, in other words, theconventional lamps are likely to consume too much power during lighting,squandering much electric power and increasing cost in case of using fora long period of time.

In addition, the conventional lamp generally gives out light directlyand thus the light is likely to scatter about in the space. Therefore,when the lamp is installed at a comparatively high location, thelighting angle of the lamp will become comparatively large and causelight diffusion and as a result, the light produced by the lamp cannotbe concentrated on an object or a place to be lighted, impossible togive out light with sufficient brightness.

SUMMARY OF THE INVENTION

The objective of this invention is to offer a high-efficiency LED lampsimple in structure, and having high working efficacy and excellentlighting effect.

The high-efficiency LED lamp in the present invention includes apositioning frame base, LED bars, a light guide plate and a power supplyunit. The positioning frame base consists of a fixing frame and a baseplate. The fixing frame is a rectangular frame having its peripheraledge extended inward vertically and formed with two opposite firstsheets and two opposite second sheets, letting the fixing frame formedwith a groove. Each second plate has its end extended outward verticallyto form a combining member. The base plate is a rectangular platepositioned at the inner side of the fixing frame and having itsperipheral edge extended and bent vertically toward one side to form anarrow sheet, letting the side surface formed with an accommodatingspace. The LED bar is formed by installing plural LEDs on a basic plateand stuck at the inner side of the sheet of the base plate by heatconduction medium. The light guide plate is received in theaccommodating space of the base plate and positioned at locations wherethe LED bars are positioned. The power supply unit is provided with adistributor at the rear side of the base plate of the positioning framebase for receiving and properly shunting AC/DC. The distributor isconnected to a DC conversion circuit for outputting DC to the LED bars.In addition, an optical film is disposed on the light guide face of thelight guide plate, able to be arranged in different modes for adjustingthe lighting angles of the LEDs.

By so designing, the DC conversion device can supply DC for the LEDs andthe optical film can be arranged in different modes for adjusting thelighting angles of the LEDs; therefore, the LED lamp of this inventionhas high working efficacy and excellent lighting effect.

BRIEF DESCRIPTION OF DRAWINGS

This invention will be better understood by referring to theaccompanying drawings, wherein:

FIG. 1 is a perspective view of a high efficiency LED lamp in thepresent invention;

FIG. 2 is an exploded perspective view of the high efficiency LED lampin the present invention;

FIG. 3 A is a first circuit diagram of LEDs connected in series in thepresent invention;

FIG. 3 B is a second circuit diagram of the LEDs connected in series inthe present invention;

FIG. 4 is a circuit conversion diagram of A.C. and D.C. in the presentinvention;

FIG. 5 is a first assembly view of the high efficiency LED lamp in thepresent invention;

FIG. 6 is a second assembly view of the high efficiency LED lamp in thepresent invention;

FIG. 7 is a third assembly view of the high efficiency LED lamp in thepresent invention; and

FIG. 8 is a fourth assembly view of the high efficiency LED lamp in thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of a high efficiency LED lamp in the presentinvention, as shown in FIGS. 1, 2, 3A and 3B, includes a positioningframe base 1, two LED bars 2, a light guide plate 3, a reflection sheet4, an optical film 5, a power supply unit 6, a protective cover 7 and anintegration frame 8 combined together.

The positioning frame base 1 consists of a fixing frame 10 and a baseplate 11. The fixing frame 10 is rectangular, made of galvanized iron,spongy iron aluminum-magnesium alloy, Teflon, carbon, or plasticmaterial like acrylics, polyvinyl chloride (PVC) or polypropylene(P.P.), and shaped by sheeting, casting or by plastic injection andformed with a thickness between 0.2 mm and 1 mm. The fixing frame 10 hasits peripheral edge extended inward vertically and formed with twoopposite first sheets 100 and two opposite second sheets 101, lettingthe fixing frame 10 formed with a groove. The two opposite first sheets100 respectively have its side edge bored with a plurality of lockingholes 1000 and convection holes 1001 and its inner side formed withplural recessed clasp points (not shown). The two opposite second sheets101 respectively have one edge extended outward vertically to form acombining member 1010 bored with a locking hole 10100.

The base plate 11 positioned at the inner side of the fixing frame 10 isrectangular, made of galvanized iron, spongy iron, aluminum-magnesiumalloy. Teflon, stainless steel or carbon, and shaped by pressing andbending and formed with a thickness between 0.2 mm and 10 mm. The baseplate 11 has its peripheral edge vertically extended and bent toward oneside to form a narrow sheet 110, letting this side surface formed withan accommodating space 111, and its side edge formed with pluralprojecting points 1101 to be correspondingly engaged with the recessedclasp points at the inner side of the fixing frame 10 for securing thebase plate 11 together with the fixing frame 10.

The two LED bars 2 are respectively formed by plural high efficiencyLEDs 20 connected in series and fixed on an aluminum basic plate 21 bytin welding. The two LED bars 2 are respectively positioned on the innerwall of the two opposite narrow sheets 110 of the base plate 11 to makeup a light source of this invention. The LEDs 20 are first connected inparallel with a zener diode 22 and then connected in series, or, duringbeing produced, the LEDs 20 are first connected in parallel with a zenerdiode 22 and then packaged. Thus, when any one of the LEDs 20 on the LEDbars 2 causes trouble, electric current 20 can continuously flow via thezener diode 22 for insuring the other LEDs 20 to work normally.

The light guide plate 3 is received in the accommodating space 111 ofthe base plate 11 and positioned at places where the two LED bars 2 arelocated. The light guide plate 3 is transparent, having two oppositeside edges respectively being light-transmitting and facing the LED bar2, and the other two opposite side edges respectively being an opaque.The light guide plate 3 can have its inner and outer side respectivelyprovided with some optical dots to make up a dot face 30 by thermalpressing, injection, inkjet or printing, and the optical dots on theother side of the light guide plate 3 are processed to form a smoothlight guide face 31.

The reflecting sheet 4 is stuck on the dot face 30 of the light guideplate 3.

The optical film 5 containing a diffusion sheet 50, an upper prism sheet51 and a lower prism sheet 52 is positioned on the light guide face 31of the light guide plate 3. The light guide plate 3 and the optical film5 respectively have its interior processed to form specific-shapedapertures for adjusting the light refracting angles attained by thelight guide plate 3 and the optical film 5.

The power supply unit 6 is provided with a distributor 60 at the rearside of the base plate 11 of the positioning frame base 1 for receivingand properly shunting AC/DC. The distributor 60 is connected with twosets of electric wires, which are respectively connected to two DCconversion circuits via an aerial adapter 61 to output DC for supplyingthe LED bars 2 with electricity. The DC conversion circuits are coveredup by a box made of insulating gaskets and then placed in the interiorof an aluminum square tube 62, and afterward the square tube 62 has itsupper and lower opening respectively sealed by a side plate. The squaretube 62 and the side plates can protect the interior circuits from beingbumped by external things. And when the DC conversion circuits work andproduce high temperature, the aluminums square tube 62 and side platescan quickly dissipate and exhaust out the heat energy to attain effectof heat dissipation.

The protective cover 7 plate-shaped is assembled at the inner side ofthe positioning frame base 1 and positioned at the front side of thelight guide plate 3 (or the optical film 5) for screening and protectingthe LED bars 2 and the light guide plate 3 (or the optical film 5),achieving water-proof, filth-resisting and weather-proof effects. Theprotective cover 7 can be made of acrylics, PC or PVC added withanti-scraping and anti-filth nano-material to enable the high efficiencyLED lamp of this invention to be employed outdoors or indoors.

The integration frame 8 is disposed at the rear side of the base plate11 of the positioning frame base 1, formed with a shape matching withthe outline of the fixing frame 10. The integration frame 8 is made ofgalvanized iron, spongy iron, stainless steel, or plastic material likeacrylics or PVC, and shaped by sheeting, casting or plastic injectionand formed with a thickness between 0.2 mm and 1 mm. The integrationframe 8 has its opposite long edges respectively bored with plurallocking holes 80 corresponding with the locking holes 1000 of the firstsheet 100 of the fixing frame 10 and its opposite short edgesrespectively protruding out to form an extension member 81 correspondingwith the combining member 1010 of the fixing frame 10 and bored with alocking hole 810. Thus, the combining members 1010 of the fixing frame10 and the extension members 81 of the integration frame 8 can be lockedtogether by locking members 82 to let the integration frame 8 integratethe base plate 11, and the distributor 60 and the square tube 62 of thepower supply unit 6 and firmly position them on the fixing frame 10.

In assembling the high efficiency LED lamp of this invention, firstly,the two LED bars 2 are respectively installed on the inner wall of thesheet 110 at the opposite ends of the base plate 11 and then the lightguide plate 3 is positioned at the inner side of the base plate 11 andclamped between the two units of LED bars 2, letting the light-emittingportion of the two LED bars 2 respectively face the light-transmittingedges of the light guide plate 3. Next, the reflection sheet 4 is pastedon the dot face 30 of the light guide plate 3, and the diffusion sheet50, the upper prism sheet 51 and the lower prism sheet 52 of the opticalfilm 5 are orderly pasted on the light guide face 31 of the light guideplate 3 and then the protective cover 7 is assembled at the front sideof the optical film 5. Subsequently, the base plate 11 together with thelight guide plate 3 and the optical film 5 and the protective cover 7are together assembled at the inner side of the fixing frame 10 of thepositioning frame base 1 to have the projecting points 1101 of the baseplate 11 respectively engaged with the recessed clasp points of thefixing frame 10. Afterward, the two square tube 62 having DC conversioncircuits disposed in the interior are respectively installed at theinner opposite sides of the fixing frame 10, and the distributor 60 ispositioned at the rear side of the base plate 11 and then the lockingmembers 82 are respectively inserted through the locking hole 10100 atthe opposite sides of the fixing frame 10 to firmly fix the square tubes62 in position. Lastly, the square tubes 62 and the distributor 60 ofthe power supply unit 6 are set in position by the integration frame 8and then the locking members 82 are respectively inserted through thelocking holes 80, 810 of the integration frame 8 and the locking holes1000, 10100 of the fixing frame 10 to threadably lock the integrationframe 8 and the fixing frame 10 together to finish assembling the highefficiency LED lamp.

Thus, after the LED bars 2 receive the DC converted and supplied by theDC conversion circuit and produce light source, the traveling directionof the light source will be guided by the light guide plate 3 and thereflection sheet 4 on one side of the light guide plate 3.Simultaneously, the diffusion sheet 50 of the optical film 5 willfunction to evenly distribute the light, and the upper and the lowerprism sheet 51, 52 will function to concentrate the dispersing light andemit light in a right direction, thus able to elevate lightingbrightness and attain effect of fully lighting.

Referring to FIG. 4 (a flow chart of DC conversion circuit), since theluminous brightness of LED is in direct proportion with electric currentflowing through the LED, the LEDs 20 of the invention are connected inseries for matching with high-voltage and low-current DC supplied by thepower supply unit 6 to enable the LEDs 20 to give out light with maximumefficiency. The DC conversion circuit that outputs constant current willgradually output steady current in accordance with the following flowprocess:

After passing through a fuse, external AC/DC will first flow through acurrent surge protective circuit (NIC) (6 a in FIG. 4) to have circuittemperature detected by a thermistor for protecting from power overload.Then, the AC flows to a doubler rectifier diode (6 b in FIG. 4) to beconverted into DC to have the voltage, output by the doubler rectifierdiode, adjusted through the line voltage of a line select (6 c in FIG.4). After rectified, the DC gets to a switching transistor (6 d in FIG.4) for lowering the voltage input into the switching transistor tobecome voltage needed to be output. After having voltage lowered by theswitching transistor (6 d in FIG. 4), the DC is filtered through theswitching inductor of a wave filtering circuit (6 e in FIG. 4) to getrid of noise signals produced during switching and then filtered througha filter capacitor (6 f in FIG. 4) to let the voltage output smoothlyand steadily. Subsequently, the output voltage is connected with acurrent shunter (6 g in FIG. 4) for outputting steady current to the LEDlamp 2 (6 h in FIG. 4).

When the temperature of LED gradually increases, the working forwardvoltage of the LED will gradually decrease and the electric currentpassing through the LED will increase to influence the lightingbrightness and the service life of the LED. Therefore, the LED lamp ofthis invention is provided with the DC conversion circuit for adjustingvoltage according to the working temperature of the LED. When the DCconversion circuit detects that the working temperature of the LED isover 60° C., the DC conversion circuit can timely function to modulatethe LED to be a proper working forward voltage value through frequencymodulation for stabilizing the current flowing through the LED andkeeping the working temperature of the LED at 60° C. so as to maintainthe lighting brightness and the service life of the LED.

In addition, the output terminal of the circuit is provided with anoverload voltage protective circuit (O.V.P.) (6 i in FIG. 4) and anoverload circuit protective circuit (O.C.P.) (6 j in FIG. 4) fordetecting the feedback compensating circuit made by the overheatprotective circuit (O.T.P.) (6 m in FIG. 4) and the constant-currentreference circuit (C. C.) (6 k in FIG. 4) of a high temperatureprotective lamp. After circuit compensation, a pulse width modulationcircuit (PWM) (6 n in FIG. 4) will automatically modulate the switchingfrequency of the switching transistor (6 d in FIG. 4) for modulatingoutput current value. Thus, when the current of the LED changesviolently due to unsteady voltage, the power supply unit 6 of thisinvention can timely modulate output the current to be output to avoidthe LED resulting in insufficient brightness because of unsteadycurrent.

In assembling and using, as shown in FIG. 1 and FIGS. 5-8, the highefficiency LED lamp of this invention can be singly installed at aproper location of a space to be used as a common lamp, such as a walllamp, an advertising lamp and the like, or have several sets of the LEDlamps connected in series to make up a long bar-shaped lamp, as shown inFIG. 5, and then have a decorative cover 90 covering up the connectingelectric wires exposed between every two LED lamps for achieving effectof beautification. The LED lamp of this invention can also be installedwithin a standard positioning frame 91 set up on a ceiling by having thecombining members 1010 at the opposite sides of the fixing frame 10leant against and fixed with the positioning frame 91 on the ceiling.The fixing frame 10 of this invention is designed to have a specificwidth, which is one fourth of a standard positioning frame 91. In orderwords, according to practical needs, two to four sets of LED lamps canbe optionally juxtaposed in the positioning frame 91 in cooperation withlarge-sized separating plates 92 and small-sized separating plates 93 tomake up a comparatively large light emission face to be employed forillumination in a large space, such as a parlor, an office or aclassroom. Further, the opposite first sheets 100 of the fixing frame 10have their side edges respectively bored with numerous convection holes1001, able to elevate heat dissipating effect of the LED lamp of thisinvention. Therefore, when the LED lamp of this invention is stuck onthe positioning frame 91 by the opposite combining members 1010 of thefixing frame 10, the first sheets 100 of the fixing frame 10 have to beextended out of the surface of the positioning frame 91, letting theconvection holes 1001 at the side edges of the first sheets 100communicate with the outside space. Thus, high temperature produced inthe interior of the LED lamp during lighting can be exhausted outthrough the convection holes 1001 to enable the LED lamp to dissipateheat effectively.

In addition, according to different conditions of environment and space,the optical film 5 of this invention can be arranged in various modesfor producing different-angled lighting, as indicated in the followingtable.

Mode of arrangement Lighting angle One diffusion sheet  120°~180° Twodiffusion sheets   95°~155° Three diffusion sheets 67.5°~127.5° Onediffusion sheet + one prism sheet   85°~145° One diffusion sheet + oneprism sheet + 47.5°~107.5° one prism sheet One diffusion sheet + oneprism sheet + 57.5°~117.5° one diffusion sheet One diffusion sheet + oneprism sheet +   30°~80° one prism sheet + one diffusion sheet

This table shows that when the LED lamp of this invention is installedat a height of 2.5 meters, different arranging modes of the optical film5 will produce different lighting angles.

When only one diffusion sheet of the optical film is used, the lightingangle is 120°˜180°; when three diffusion sheets are used, the lightingangle becomes 67.5°˜127.5°; when one diffusion sheet and one prism sheetare used, the lighting angle attains to 85°˜145°, and when one diffusionsheet, one prism sheet, another prism sheet and another diffusion sheetof the optical film are used, a comparatively concentrated lightingangle of 30°˜80° can be obtained.

Thus, according to foresaid different arranging modes of the opticalfilm 5, installment of the LED lamp of this invention in a space can bedesigned differently. For instance, if two sets of the LED lamps areinstalled in the positioning frame on a ceiling 250 meters above theground, and the LED lamp is disposed with three diffusion sheets, thelighting angle of the LED lamp, measured from the ground, is 125°, andthe illumination is 200 lux and the whole lumen value is 4800. If foursets of the LED lamps are assembled in the positioning frame on aceiling 250 meters above the ground, and the two sets of LED lamps atthe opposite sides are respectively disposed with only one diffusionsheet and the central two sets of LED lamps are respectively disposedwith one diffusion sheet and one prism sheet, the lighting angle of theLED lamp, measured from the ground, is also 125, but the illuminationbecomes 403˜1000 lux and the whole lumen value is 9600.

To sum up, the arrangement modes of the optical film of the LED lamp ofthis invention can be adjusted in accordance with space, height andlighting requirement for attaining different lighting angles, able toachieve a maximal lighting effect.

While the preferred embodiment of the invention has been describedabove, it will be recognized and understood that various modificationsmay be made therein and the appended claims are intended to cover allsuch modifications that may fall within the spirit and scope of theinvention.

1. A high efficiency LED lamp comprising: a positioning frame basecomposed of a fixing frame and a base plate, said fixing frame being arectangular frame having its peripheral edge extended inward verticallyand formed with two opposite first sheets and two opposite secondsheets, letting said fixing frame formed with a groove, each said secondsheet having its edge extended outward vertically to form a combiningmember, said base plate disposed at the inner side of said fixing frameand having its peripheral edge vertically extended and bent to one sideto form a narrow sheet to let said one side formed with an accommodatingspace; LED bars respectively composed of plural LEDs installed on abasic plate, said LED bars stuck on the inner wall of said sheet of saidbase plate of said positioning frame base by heat-conduction medium; alight guide plate being a transparent plate having one side surfaceformed with a dot face and the other side surface formed with a lightguide face, said light guide plate received in said accommodating spaceof said base plate at locations where said LED bars are positioned, anda power supply unit assembled at rear side of said base plate of saidpositioning frame base, said power supply unit provided with adistributor for receiving and properly shunting AC/DC, said distributorconnected to a DC conversion circuit for outputting DC to said LED bars.2. The high efficiency LED lamp as claimed in claim 1, wherein saidfirst sheet of said fixing frame has its inner side formed with aplurality of recessed clasp points, and said sheet of said base platehas its side formed with projecting points to be correspondingly engagedwith said recessed clasp points.
 3. The high efficiency LED lamp asclaimed in claim 1, wherein said first sheet of said fixing frame hasits side edge bored with lots of convection holes for dissipating heat.4. The high efficiency LED lamp as claimed in claim 1, wherein LEDs onsaid LED bars are connected in series.
 5. The high efficiency LED lampas claimed in claim 4, wherein said LEDs are connected in series with azener diode before being packaged and produced.
 6. The high efficiencyLED lamp as claimed in claim 4, wherein said LEDs are first connected inparallel with a zener diode and then connected in series.
 7. The highefficiency LED lamp as claimed in claim 1, wherein a reflection sheet isdisposed at one side of said dot face of said light guide plate.
 8. Thehigh efficiency LED lamp as claimed in claim 1, wherein an optical filmis disposed at one side of said light guide face of said light guideplate.
 9. The high efficiency LED lamp as claimed in claim 1, wherein aprotective cover is assembled at the inner side of said positioningframe base and the front side of said light guide plate.
 10. The highefficiency LED lamp as claimed in claim 1, wherein an integration frameis set at a rear side of said positioning frame base and has itsopposite end edges respectively extended outward to form an extensionmember corresponding with said combining member of said fixing frame,said combining members and said extension members closely lockedtogether by means of locking members.
 11. The high efficiency LED lampas claimed in claim 1, wherein said DC conversion circuit of said powersupply unit consists of a current surge protective circuit, a doublerrectifier diode, a switching transistor, a switching inductor, a filtercapacitor, a current shunter, an over voltage protective circuit, anover current protective circuit, an over heat protective circuit, aconstant current reference circuit and pulse width modulation circuit,said circuits electrically connected for supplying said LED with steadycurrent.